Japan Shuts Nuclear Plant After Leak

By MARTIN FACKLER

Published: July 18, 2007

Japanese authorities suspended operation of a nuclear power plant on Tuesday after a radiation leak and other damage from a deadly earthquake raised new concerns about the safety of the nation's accident-plagued nuclear industry.

Tokyo Electric Power, which operates the nuclear plant near Kashiwazaki, a city in northwestern Japan, said it had found more than 50 problems at the plant caused by the earthquake on Monday. While most were minor, the largest included 100 drums of radioactive waste that had fallen, opening the lids on some, the company said.

The earthquake also caused a small fire at the plant and caused 317 gallons of water containing trace levels of radioactive materials to leak into the Sea of Japan, the company said. On Tuesday, the company announced that it had detected tiny amounts of radioactive material in an air filter in one of the plant's seven reactors. But it said it was unlikely that the material had entered the atmosphere.

The company said that it was still examining how the tainted water got out, but that the levels of radioactivity were too low to endanger people or the environment.

Prime Minister Shinzo Abe criticized Tokyo Electric for being ''too slow'' in reporting the problems to the government and the public.

''Nuclear power can only operate with the people's trust,'' Mr. Abe told reporters on Tuesday. Power companies ''must accurately and swiftly report what is happening.''

Television videotape showed rescuers digging through buildings in Kashiwazaki that had been toppled by the earthquake, which the local police said had killed at least nine people and injured an additional 1,000. Japan's meteorological agency said the quake measured 6.8 in magnitude, while the United States Geological Survey put the magnitude at 6.6.

Japan's military used warships and trucks to carry rice balls, bread and water to the remote region in Niigata Prefecture, about 160 miles northwest of Tokyo. But relief efforts were slowed by landslides and gapping cracks in the earth that severed rail lines and roads, local news media reported.

About 13,000 residents fled their homes, Japanese news media reported. Television videotape showed many people sleeping on blankets and futons in school gymnasiums that were being used as shelters.

In Tokyo, government ministers scrambled to reassure the public about the safety of Japan's nuclear power plants, which have had a string of accidents, at least one of them deadly, and cover-ups of incidents in recent years. The economic ministry, which regulates the power industry, moved swiftly to reprimand Tokyo Electric for not reporting the leak to authorities until about six hours after discovering the problem. The ministry also ordered suspension of operations at the plant, the world's largest by amount of electricity produced, until safety could be ensured, and dispatched a team of inspectors to survey the damage.

The power company said a cause of the damage was that the force of the shaking from the earthquake had exceeded the design limits of the reactors, suggesting that the plant's builders had underestimated the strength of possible earthquakes in the region.

The chief government spokesman, Yasuhisa Shiozaki, said the designs of other nuclear plants may also have to be re-examined to make sure they are strong enough to resist all potential earthquakes.

Nuclear safety can be a particularly delicate issue in Japan, the only nation to be attacked with atomic weapons, in Hiroshima and Nagasaki in 1945. Nuclear safety experts said authorities apparently feared the earthquake-related accidents could raise fresh public doubts about Japan's 55 nuclear reactors, which the nation relies on for about a third of its electricity and to lessen energy dependence on the Middle East.

''This will stir new debate about whether nuclear plants are safe enough,'' said Haruki Madarame, a professor in nuclear safety engineering at the University of Tokyo. ''Authorities will have to show the public that they are taking all reasonable steps to ensure safety.''

Japan is one of the most earthquake-prone nations in the world, and has strict regulations meant to prevent earthquake damage to its nuclear plants. Those include building nuclear plants on solid bedrock to limit shaking from earthquakes, and erecting walls to protect against tsunamis at plants along the coast, like the Kashiwazaki plant.

Tokyo Electric said the damage from the earthquake did not threaten the safety of the reactors at the Kashiwazaki plant. Four reactors were operating at the time, and all shut down safely, Tokyo Electric said.

Nuclear safety experts said the earthquake struck as power companies were examining reactors to see if they met safety standards revised last September. They said the unexpected strength of the earthquake's tremors may force authorities to set even tougher standards, and carry out fresh seismic studies to determine if they were underestimating the size of potential earthquakes.

The Kashiwazaki plant was shut down as Tokyo faced its peak power use during the summer. In March, another nuclear plant operator, Hokuriku Electric Power Company, shut down a reactor after admitting it had covered up a 15-minute uncontrollable nuclear chain reaction in 1999. Three years ago, Japan's deadliest nuclear accident killed four workers at a nuclear plant in Mihama when a steam pipe burst.

Photo: Smoke from a reactor fire hung over a nuclear plant run by Tokyo Electric Power near Kashiwazaki, in northwestern Japan on Tuesday, a day after an earthquake that also caused a radiation leak and other problems. (Photograph by Japan Coast Guard, via European Pressphoto Agency)